This circuit was obtained in an American documentation from the 80's. The transistors can be equivalent to those indicated and the crystal can reach a few tens of megahertz.
You can program the 4018 in other ways, as shown in the figure. In this 7 divider configuration, for...
July 2017 - The new Mean Well ENC-360 360 W battery chargers suitable for motorcycle battery...
This circuit was found in a 1982 Maplin magazine (England Component Store). The circuit has...